1. Field of the Invention
The present invention relates to a flat panel display device for displaying an image on a flat panel, and more particularly, to a picture mode controller for selecting one of a video image and a black image on a flat panel, a flat panel display device including the same, and a driving method thereof.
2. Discussion of the Related Art
Flat panel displays such as general liquid crystal panels, plasma display panels, and electro luminescence display panels include pixels formed in respective unit regions defined by scan lines (gate lines) and data lines (source lines). A flat panel display can provide a large screen while having a remarkably thin thickness compared to a cathode ray tube (CRT). Furthermore, flat panel displays make it possible to manufacture image display devices having a slim profile and light weight.
Video data corresponding to an image to be displayed on these flat panel displays are supplied in the form of a pixel data stream to the flat panel display device from a video source including a graphic card of a computer system, and a video demodulating unit of a television receiver. Timing signals including data clock and data enable signals are transmitted together with the video data. These timing signals indicate the period of pixel data and the section where pixel data are present to allow the flat panel display device to accurately receive video data.
During an initial booting when a video source has not been initialized, a portion of timing signals are not generated for a predetermined time and another portion of timing signals are generated in a state (i.e., an abnormal state) wherein the timing signals do not coincide with timings of the video data. During the initial booting, data enabling signals are not generated while data clock is generated in a state (i.e., an abnormal state) where the period of the data clock does not coincide with the timing of video data. When a portion of timing signals are absent, a flat panel display device cannot accurately receive video data. Accordingly, an abnormal image totally different from an original image is inevitably displayed on a flat panel.
Also, when the resolution mode of an image to be displayed on a flat panel changes, timing signals temporarily have an abnormal form that does not coincide with video data. Both data enable signals and data clock do not coincide with the timing of video data temporarily. Due to these abnormal timing signals, a flat panel display device cannot accurately receive video data. Accordingly, an abnormal image totally different from an original image is inevitably displayed on a flat panel.
Furthermore, timing signals transmitted together with video data can be interfered and distorted by noises while they are transmitted from a video source to a flat panel display device. Due to this distortion, the flat panel display device cannot accurately receive video data. Accordingly, an abnormal image totally different from an original image may be displayed on the flat panel display.
To prevent an abnormal image from being displayed, a method of displaying a black image has been used in a related art flat panel display device. According to the method of displaying the black image, receiving video data and driving a liquid crystal (LC) panel are performed based on a received data enable signal or a pseudo enable signal depending on whether the data enable signal is present among timing signals from a video source. In other words, when a data enable signal is received, an image is displayed based on the received data enable signal. On the other hand, when the data enable signal is not received, a black image is displayed based on a pseudo enable signal.
However, since a video image and a black image are selectively displayed depending on whether a predetermined timing signal is present, an abnormal image is still displayed on a flat panel display when the resolution mode of an image changes. In addition, when timing signals (particularly, data enable signals) are distorted due to noises, an abnormal image is displayed on a flat panel display. The abnormal image greatly reduces the reliability of a flat panel display device.